Clockwork-testing machine



Jan. 5 192.6.

o. JUNGHANS cLocxwoRx TETING nenni:

Filed August 4;. 1924 3 shuts-Sheet 1 wir v J-ar Jam-5 192e. y 1,568,404

o. JUNGHANS CLOCKWORK TESTING MACHINE Filed August 7, 1924 3 Sheets-Sheet 2 venan' Jan. 5 ,1926.

O. .JUNGHANS CLOQKWORK TESTING -HACHINE Filed August '7, 1924 3 Sheets-Sheet 3 fw ven/212%.'

@wher 3ans I Patented Jan. 5, 1926.

UNITED STATES PATENT OFFICE` OSKAR JUNGHANS, OF SCHRAMBERG, GERMANY.

CLOCKWORK-TESTING MACHINE.

Application led August 7, 1924. Serial No. 730,792.

To all far/mm t muy conce rn Beit known that I, Dr. OsK-AR JUNG- HANS, director, a citizen of the German Republic, residing at N o. 134 oi Galshaldenerstrasse, Schramberg, Germany, have irlvented lcertain new and useful Improvements in Clockwork-Testing Machines, of which the following is a specification.

My invention relates to an improved clock-work testing machine and my invention also includes a new and useful machine for carrying the improved method into effeet.

-The method hitherto employed for the like purpose consists in hanging up a weight by a suitable member of the clockwork to be examined to actuate the latter .so that the clock-work in itself, however',

- in the method hitherto practised.

Cil

The object of my invention is to remedy this defect. lViththis aim in view or, in other words, in order to reduce reliable and efficient clock-works or use in time fuses and the like, I examine and regulate the clock-work, according to this invention, in such a manner that the prevailing conditions are similar to those of a flyingprojectile fitted with a time fuse having a clock-work of the kind under examination or regulation.

` Accordingly my invention, viewed from its broadest aspert, resides in causing the clock-work to be regulated to revolve, while in a locked state, that is to say with its movable parts locked so that-they will not run, then to be unlocked as soon' as a rotary running speed similar to that in'a dying projectile is attained, and thereupon to be locked again automatically, after a predetermined time the arrangement being such that the single releasing or unlocking operations are successively accomplished by means of electrical power and at predetermined intervals or periods of time, whereby a very simple and efficient construction of the Amachine designed for carrying out the new method or invention will be obtained.

The accompanying drawings, forming a part ot this specification, show for purposes of exeniplification, a preferred form and manner in which my invention or' method may be embodied and practised, but do not limit the claimed invention to such illustrative instance..

Figure l is an elevation of the machine, partially in section, Figure 2 is a plan thereof with the auxiliary devices required Jfor carrying out the new method, and a diagram of connections shown, Figure 2 is a continuation oi the wiring diagram of Figure Q, Figure 3 is an elevation of a part of the machine, Figure 4 is an end view thereof partly in section, and Figure 5 is a section taken on line 5-5 of Figure 1w Parts which are repeated in the several figurcs bear the same reference characters in i each case. A

Referring to Figures l and 2 the clockwork 1 to be regulated is clamped in and supported by a chuck 2 carried by the spindle 31 of a head stock 3. The spindle 31 is rotated, from any suitable source ofv -power in the usual manner customary in lathes, preferably with the aid of an appropriate transmission and by meansof a gear drive such` as a centrifugal gear or the like adapted to produce a peripheral speed as required for the regulating In the tail stock 4 the back centre 5 is securely mounted therein but is adapted to be adjusted axiallyby means of a rack and a pinion engaging therewith and operable by means of a hand Wheel 6 asshown, the arrangement being such that the saidback centre 5 can be fixed or locked in any adjusted position in the manner and by means usual in the art so that the latter need not be illustrated or explained in detail.

The back centre 5 is hollow throughout its length and a second or' internal back centre 7 is embedded to snugly lit therein. This centering member 7 is likewise hollow but not to therfull extent of its length, and

in the bore a coiled spring 71 is lodged actf ing to constantly force the member 7 in the purpose.

back centre by means ot screws or in any other appropriate way. The bar 8 serves as an abutment for the spring 71. rlhe front end, that is the end on the lett hand side in Figure 1, of the inner back centre 7 projects beyond the end of the outer back centre 5 and is provided with a cup shaped member 9 rotatably mounted relative to the back cent-re 7 but coupled therewith so that it cannot have any axial or lengthwise movability except with the member 7 as a unit.

rEhe cup 9 is provided with two pins 91 firmly connected therewith and extending parallel to the axis thereof. The chuck 2 has two holes which are adapted to receive the two pins 91 whereby `the cup can be coupled with the chuck in order to revolve in ,unison with the latter and the driving spin- `dle 31. The rear end, that is the end on the right hand side in Figure 1, ot the inner back centre 7 is rinly connected with and carries a cross head 10 having two screws 11 axially displaccable and adjustable therein. lever 12 fulcrumed ina transverse-slot 51 at `15 of the back centre 5, see Figures 1 and 5, is adapted to engage in a transverse slot of the inner back centre 7 so as to loclr and prevent the latter from moving lengthwise towards the stationary head stock under the action of its spring 71. The lever 12 is provided with a spring 121, see Figure 5, which is adapted to impart to the lever the tendency ot' maintaining a depressed position in order to engage in the transverse slot ot the inner back centre 7. An electromagnet lll is duly connected with the lever 12 so that, in case of energization, the lever will be caused to disengage from the slot and to thereby unlock the back centre 7, so that the latter then will be tree to move towards the chuck 2 under the action o' its coiled spring 71. The electromagnet lll and the operating parts belonging thereto are ot conventional construction and arrangement and therefore need not be described in detail.

Fulcrumed on the tail stock 4 are two bell crank levers 13 interconnected by tie bars to forni a unit. This unitary double lever 13 is controlled by a powerful spring 1li attached to the two outer and longer arms thereof and acting to pull the said arms downwardly while the two shorter and vertical arms ot the double lever engage the hereinbefore mentioned screws 11, respectively, thus establishing a tendency in the lever to move and displace the inner back centre 7 towards the right hand side in Figure 1 against the action or the spring 71.

A vertical rod 15 guided in suitable bearings is provided below the double lever 13 and a pedal not shown is operatively connected with the rod 15. rllhe construction and arrangements of the rod, the bearings, the connections and the pedal are of theusual type known to persons skilled in the art and to whom this specification is addressedso that a detail description thereof is deemed unnecessary. 1n operating the pedal the double lever lil is turned about its ulcrum, against the action of the spring 111, so that the tie bar 131 interconnecting the extremities of the vertical arms of the double lever will be arrested by a. spring controlled pawl or detent 16 pivoted to the tail stock and the double lever 13 will thus be locked against the action of the spring 14: on releasing the pedal.

The pawl or detent 16 is keyed to one cid ot a shaft 161 and a twoarmed lever 17 is firmly connected to the other end thereof. rlhe shaft 161 is duly supported in bearings provided in brackets on the tail stock and a .spring 171 is attached to the inner arm of the lever 17, that is the arm on the left hand side in Figure 3, the other end of said spring 171 being fixed to some stationary point of the machine. The spring 171 imparts to the lever 17 a tendency to hold the pawl 16 in engagement with the tie bar 131 of the double lever4 13. .The outer arm of the lever 17, that is the arm on the right hand side of Figure 3, supports the armature 19 of an electromagnet 1V which when energized will turn the lever 17 against the action of the spring 171 and thereby cause the pawl 16 to disengage from the tie bar 131 of the double lever 13.

Two further electromagnets I and 1I are provided in the circuit of the electrical oper ating mechanism of the machine, 'the electromagnet l' serving the purpose of initiating the beginning as well as the termination ot' the whole movementand the electromagnet ll acting, in co-ope-:ation with the clock V, to effect the measurement of time of the regulating operation and to control the other electromagnets.

The armature 2O of the electromagnet I is provided with two contact springs 21 and 22 insulated with relation to each other by means ot an insulated block 12, and a pawl.

23 is pivoted to a stationary point to act as a means for engaging the armature and holding the. same in its lowermost position, that is, liberated from the contact-pieces 43 and 44 as shown in Figure 21.v At this position of the armature the two circuits controlled by the contacts 21 and 22 are open and adapted to be closed by -disengaging the pawl 23 from the armature. The contact 22 acts to close the circuit ot' the electromagnet l while the Contact 21 closes the main circuit including the clock V acting to produce by means of its second-pendulum 32, a short current impulse each second only. Such imF pulse Flows through the coil ot the electromagnet 1l so that the armature of this electrcmagnet will be attracted once cach second whereby. through the agency of a pawl and ratchet mechanism 38, a shaft 2-1 properly yjournaled in stationary bearings is rotated,

` The shaft 24 is included' in the circuit and provided with three radial arms 25, 26 and 27 which are juxtaposed and adjustable in their peripheral relation. Pivotally mounted on a post 28 or the like are three spring controlled Contact pawls 26a and` 27a duly insulated with relation to each other and ofv which each is placed in a circuit of its own, that isl to say, in a diiferent circuit, and adapted to come in contact with the corresponding arm 25, 26 or 27 of th'e stepwise revolving shaft 24., In Figure 2 I have shown, for clearness sake, the three contact pawls in superposed loca-tion but I wish to have it understood that in reality they are arranged in juxtaposition.

The operation of the .machine is as follows I The clock-work to be regulated is clamped or otherwise secured in the clutch 2, a level' l8being provided on the kchuck for locking the balance of the clock-Work. Then the back centre 5 together with the inner back centre 7 located therewith by means of the lever 12, is to be fed towards the stationary head stock 3 by means of the hand wheel 6 until or so far thatythe cup 9 is in close proximity to the lever 18, the abutting screws 11 are in close proximity to the lever 13 and the driving ins 91 of the cup 9 engage in their res ective holes of the chuck, a's will be seen in igure 1. This done the back centre 5 is secured `by' clamping" or in any other suitable manner and the spindle 31 is then caused to rotate vin the usual way known inV lathes. -4 f p A As soon as the spindle reaches the predetermined or required maximum value or number or revolutions the key 29, Figure 21, is depressed manually with the result that the dependingv arm 30 of the key pivoted to the pawl 23 closes a contact device 31 for off for the next movee supplied to the conduit, `from the coil of the magnet I. On

the purpose of cutting continued depression of the key 29 the pawl 23 is disengaged from the armature of the electromagnet I and the armature thus re leased is lifted by its spring 27 whereby the circuit of the electromagnet II and of the clock V is closed by means of the contact 21, while the contact 22 at the saine time acts to also close the circuit of the electromagnet I which, however, is diverted oil bymcans of the contact device 31 and interrupted, the

next second through the energization of the magnet II and the feed motion of the arm 27.

- Upon releasing the key 29 the armature ofl the electromagnet II now accomplishes one stroke each second under the controlling action of the clock V-of which, for clearness sake, the pendulum only is shown in Figure 21`-and causes, by means of the pawl and ratchet device, the arm 25 to engage its contact pawl 2511, whereby the electromagnet III will be energized, see Figures 2, 4 and 5, so that the armature of the latter acts to turn the lever 12 and to thereby disengage the Same from the slot of the'inner back centre 7. The thus released back centre 7 is pushed forwards by its spring 71 towards the stationary head stock 3 so that the rim Vof the cup 9 carried by the back centreA 7, comes in contact with the lever 18 and disengages the same from the balance of the clock-work to be regulated with the result that the lafttei-then will be :tree to run.

During the running of the work thearma# y ture of the electromagnet II continues to perform its successive 'second-movements until after` a redetermmed period or number of seconds t ie arm 26 of the pawl and ratchet mechanism engages its contact pawl 26aL whereby the electromagnet IV will be energized. In consequence thereof the armature,4

19 of the electromagnet is attracted, the pawl 16 is disengaged by the armature from the tie bar 131 of the double lever 13 and the latter, thus released, tilts over under the action of the springlf to engage the screws- 11 with the result that the inner back centre 7 together with the cup 9 are-displaced in' the. direction away from the stationary head stock until the lever 12engages again in the slot of the back centre 7, so that the lever 18 of the chuck 2 will be released and catch at the balance to stop or lock the .clock-work under test.

IIhe apparatus now may be disconnected.

The electromagnet II continues to be ener- 'gized stepwise or intermittently in the meanwhile until the arm 27 of the, pawl and ratchet mechanism engages its contact pawl 2711 in order toclose the circuit of the magnet l'. Immediately thereupon the latter ati 4 Ltracts its armature whereby the whole circuit is interrupted, and the armature is thenV position by the pawl the double lever 131s tilted, over under the action of its spring 14 and its tie bar 131 is not engaged with the pawl 16. The back centre 5. after having been released, in the eventuality of still-having been locked with regard to the tail stock 1, is now returned, by means oit' the hand. wheel 6, into its orig inal or normal inoperative osition with the cup 9 reseded from the cloc -work to be regulated, so that the latter can be removed from the chuck 2.

'For the purpose of ascertaining the result of the test a. disk 11 divided and marked in seconds may be employed. This disk is fixed to the outer end ofthe main shaft or spindle of the clock-work to be tested so as to revolve therewith duringI the regulating or testing operation hereinbefore described. Upon removal of the clock-work from the chuck at the end of the operation it can be readily seen from the disk 11, whether or not its rotary motion did correspond to the running time.

In order to accomplish a further testing operation the double lever 13 must be returned by means of the pedal and the rod 15 into the position shown in Figure 1 with the tie bar 131 caught by the pawl 16. ln connection with the described apparatus a device for ascertaining the interval between the starting of the work and the impact of the tiring pin 37 on a simulated primer 36 (Figure 2) may be employed. As shown in the drawing an insulated contact piece 32 attached to the cross head 10 is adapted to close the circuit of an electromagnet VI by cooperating with a contact member 38 pro-l vided on the machine frame, as soon as the back centre 7 causes the clock-work to run owing to its advance in the direction towards the spindle 31. flihe pivoted armature et() of the said electromagnet V is energized. But as Soon as the tiring pin of the fuse strikes the primer 36, the magnet Vl will be cut out automatically so that the counter is stopped and the interval between starting and stopping can be read.

rIhe means for automatically cuttingout the electromagnet VI is of the following construction and arrangement. The circuit of the electromagnet includes a contact piece 3d adapted to be opened by means of an auX- iliary electromagnet VIII. The circuit of the latter leads, on the one hand, to the machine frame, that is the clock-work 1 and the tiring pin 37, and on the other hand to a brush 35 adapted to slide on an insulated slip-ring 38 mounted on the spindle 31. IThe slip-ring is electrically connected to a copper Contact 86 (the simulated primer) by means of an insulated conduit 39 passing through the spindle 31, the tiring pin 37 when released to drop, meeting the said contact 3G and thus closing the circuit of the magnet VIH which in turn opens the contact 34: so that the magnet Vi will be deenergized.

From the foregoing it is believed that the advantages and novel features of my invention will be readily understood and, therefore, further detail description is deemed unnecessary.

'ln reducing my invention to practice l nd that the form described and shown is a most practical, eiiicient and preferred embodiment, but realizing that certain conditions will necessarily vary in concurrence with the adaption of my machine, I desire to emphasize the fact that various minor changes in the details of construction and in the proportion of parts may be resorted t0 when required or desired without thereby sacrificing any of the advantages of my invention as defined in the appended claims.

l/Vhat claim is 1. A. method of testing the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, consisting in causing aclock-work, while its running parts are in a locked oondition, to revolve as a whole, unlocking the said running parts automatically when a rotary speed corresponding to that in a iying projectile is attained and locking the same again automatically yafter a predetermined running period.

2. A. machine for testing the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination and arranged inl thc manner of a lathe, a member for supporting and holding the clock-work to bc tested, means connected with the said member and adapted to lock and unlock the running mechanism of the said clock-work, a head stock with a spindle carrying the said member, a tail stock, two conaxial back centres supported in the latter, a rotatable coupling member` at the one end of the one back centre, and a spring in the latter, substantially as and for the purpose set forth.

3. Amachine for testing'the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination a chuck for supporting and holding the clockwork to be tested, a locking lever connected with the said chuck and adapted to lock and unlock the running mechanism of the said clock-work, a head stock with a spindle carrying the said chuck, a tail stock, two conaxial back centres supported in the latter, a

rotatable coupling member at the one end of the one back centre, and a spring inthe latter, substantially as and for the purpose set forth.

a. A machine for testing the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination a chuck for supporting and holding 'the clock-work to be tested, a locking lever connected to the 5. A method of testing the performance of clock-works to determine the effects of centrifu al action which consists in the steps of rapi ly rotating the clock-work to be tested, starting the clock-work to operate while under rapid rotation, and then stoppingvthe operation of the clock-work after a prede operate while under rapid rotation, and then stopping the operation of the clock-Work after a predetermined running time.

7. A method of testing the performance of clock-works to determinethe effects of centrifugal action which consists in the steps of rapidly rotating the clock-work at a predetermined speed and while the clock-wo rk :s in a non-running condition, automatically starting the cloc -work to operate while under the uniform lpredetermined rotation, stopping Vthe operation of the clock-work after a predetermined' running time, and then stopping the rotation of the clock-work.

A machine for Vtesting the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination a mem ber for supporting and holding the clockwork to be tested, means connected to the said member and adapted to lock andunlock the running mechanism of the said clockwork, a stationary head stock with a s indle carrying the said member, a tail stoc two conaxial back centres supported in the latter, a rotatable coupling member at the one end 0f the one back centre, a spring in the latter, and a sy tem of releasin electroma ets construe d and arrange substantial y as set forth for the purposespecified.

9. A machine for testing the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination a member for supporting and holding the clock-work under examination, a means connected to the said member and adapted to lock the' running mechanism of the said clock-work, a stationary head stock with a spindle carrying the said member, a tail stock,. two conaxial back centres supported in the latter, a rotatable coupling member at one end of one of the back centres, a spring in the latter, an electrical system inc uding 'releasing electromagnets, and a chronometer, the arrangement being such that the electromagnets are energized ac cording .to predetermined intervals coiitrolled b the said chronometer, substantially as an for thepurpose set forth.

10. A machine for testing the performance of clock-works to be driven by centrifugal action, preferably for use in mechanical time fuses, comprising in combination a member for supporting and holding the clock-work under examination, a means connected to the said member and adapted to lock the running mechanism of the said clock-work, a stationary head stock with a spindle carrying the said member, a tail stock, two coiiaxially arranged back centres supported in the latter, a rotatable coupling member at the end of one of the back centres, a spring in the latter, an electrical system including` releasing electroni-aguets, a chronometer, and a pawl and ratchet device, the

varrangement being such, that the said chronometer actuates, by means of one of the electromagnets, the said pawl and ratchet device in order to close the circuits of the several electromagnets in a predetermined succession, substantially as and for the pui'- pose set forth.

l1. A machine for testing theperforinance of clock-works to determine the effects of centrifugal action comprising a head stock, a chuck rotatably mounted in said head stock and adapted to receive the clockwork to be tested, a leverV on the chuck for locking and unlocking the, balance of the clockwork, a tail stock associated -with said head stock, a cup in said tail stock adapted to be coupled with the chuck and movable axially, and means for moving said cup against the lever in order to release the balance of the clockwork. i

12. A machine for testing the performance of clock-works to determine the effects of centrifugal action comprising a lathe which is adapted to rotate the clock-work to'be tested at a redetermined speed, means associated witli the lathe for locking and unlocking the balance of the clock-work to be tested While the clock-work is in rotation;

and means for timing the operation of the lathe.

13. A machine for testing the performance of clock-works to determine the effects of centrifugal action comprising a lathe which is adapted to rotate the clock-Work, means for locking the balance of the clock-work to be tested during rotation, and means for actuating the first-named means for unlocking the balancexduring rotation, said two means being associated with the lathe.

14. A machine for testing the performance of clock-works to determine. the effects of centrifugal action coiiiprisin a lathe which is adapted to rotate the doeii-work, a lever pivotally mounted on a chuck of said lathe and adapted to look the balance of theclock work, and means for actuating the lever while the clockwork is rotating'.

15. A machine for testing the performance of clock-works to determine the effects of centrifugal action comprising a lathe which is adapted to rotate the clock-work, means in the lathe for locking and unlocking the balance of the clock-Work, an electrical circuit associated with said lathe comprising an electro-magnet, a pendulum of a clock, a pair of contacts, said electro-ma' et being adapted to close the circuit throng the pendulum andthe contacts, and a second electro-magnet operated by the successive closing of the contacts With the pendulum and adapted to operate the means to unlock the balance of the clock-Work.

16. A machine for testing the performance of clock-Works to determine the effects of centrifugal action comprising a lathe which is adapted to rotate the clock-Work and having locking and unlocking means associated therewith, and an electrical circuit associated With the lathe comprising an electro-magnet, a pendulum of a clock, a pair of contacts, said electro-magnet being adapted to close the circuit through the pendulum and the contacts, and a second electro-magnet operated by the successive closing of the contacts with the pendulum which is adapted to operate the locking and unlocking n means of the lathe.

17. A machine for testing the perfo'irnance of clock-Works to determine the effects of centrifugal action comprising means for rotating the clock-Work 'to be tested and having locking and unlocking means for the balance of the clock-Work; and an electrical system comprising means for operating the unlocking means in order that the clock-Work may operate, and meanr` for locking the balance of the clock-Work after a predetermined running time.

18. A machine fortesting the performance of clock-works to determine the effects of centrifugal action comprising means for rotating the clock-Work to be tested and having locking and unlocking means for the. balance of the clock-Work; and an electrical system comprising meansfor operatin the unlocking means in order thatthe c ock- Work may operate, a second circuit, a pendulum of a clock for timing the duration of the test, said second circuit being controlled by the pendulum and is switched in by said means of the electrical' system, and means for locking the balance of the clockv work after a predetermined running time.

19. A machine for testing the performance of clock-works to determine the eects of centrifugal action comprising means for ro tating the clock-work to be tested and hav in locking and unlocking means furthe ba ance of thefclock-Work; and an electrical system comprising an electro-magnet, a. second circuit controlled by said electromagnet, a pendulum of a clock for timing the duration of the test and which is adapted to control said second circuit, and a second electro-magnet for locking and unlocking the balance of the clock-Work.y

a'aeacoa 20. A machine for testing the performance of clock-Works to determine the effects of centrifugal action comprising a lathe for rotating the clock-Work to be tested and hav-- ing locking and unlocking means for the balance of the clock-work; electro-magnets adapted to operate said means; and an electrical system comprising an electro-magnet, a second circuit controlled 'by said electromagnet of said system, a pendulum of a clock for timing the duration of the test, and a second electro-magnet for energizing the magnets which control the locking and unlocking of the balance of the clock-Work.

2l. A machine for testing the performance of clock-Works to determine the effects of centrifugal action comprising a lathe for rotating the clock-Work to be tested and havinf locking and unlocking means for the balance of the clock-Work; electro-magnets adapted to operate said means; and an electrical system comprising an electro-magnet, a pendulum of a clock for timing the duration of the test, a second circuit control-led by said pendulum, and a second electromagnet actuated by the oscillation of the pendulum and adapted to close successive contacts which are in circuit with the mag nets of the locking and unlocking means of the lathe.

22. A machine for testing the performance of clock-Works to determine the effects of centrifugal action comprising a lathe for rotating the clock-Work to be tested and having locking and unlocking means for the balance of the clock-Work; electro-magnets adapted to operate said means,- and an electrical system comprising an electro-magnet, a pendulum of a clock fory timing the duration of the test, a second circuit controlled by said pendulum, a switch for o erating the lastnamed electro-magnet, andp a second electromagnet actuated by the oscillation of the pendulum and adapted to close successive contacts which are 1n circuit with the magnets of the locking and unlocking means of the lathe.

23. A machine for testing the performance of clock-Works to determine the effects of centrifugal action comprising a lathe for rotating the clock-Work to be tested and having locking and unlocking means for the A ,of the' locking and unlocking means of the lathe.

24. A machine for testing the performance of clock-works to determine the effects of centrifugal action comprising a lathe for rotating the clock-work tobe tested and hav- 1n locking and unlocking means for the bala nce of the clock-work; electro-magnets adapted to operate said means; and an electrical system comprisin an electro-ma et, a pendulum of a clock or timing the (filation of thetest, a second circuit controlled by said pendulum and said last-named electro-magnet, a pair of contacts adapted to c0- operate with said pendulum for closing a circuit at each end of an oscillation, a switch for operating the last-named electro-magnet,

of clock-works to determine the effects of 25.

centrifugal action comprising a device for, y. rotating the clock-work to be tested at al predetermined speed, andv means associated with said device for locking and unlocking the balance of the clock-work to be tested 30 while the clock-work is rotating.

In testimony whereof I affix my signature.

y OSKAR JUNGHANS. 

